News » Archive » PC Tip: Dual Channel memory in a Laptop

Recently, [Dell][1] had a [gonga coupon][2] on their [Inspiron laptops][6], and we purchased one to run [Linux][3], [OpenBSD][4], and [Windows][5], for network and interoperability testing. Dell ships these with slower memory, so we wanted to see how faster memory would improve performance (and also increase the memory size for less than what Dell charges).

The machine we ordered is an [Inspirion 6000][6], with a Pentium M 730 (1.6GHz), which has a 533Mhz Front Side Bus (which connects the processor to the rest of the system). Dell ships these with a single 256MB module of PC2-3200 (AKA DDR2-400) memory. The [Mobile Intel 915PM Chipset][7] that this model uses supports faster PC2-4200 (AKA DDR2-533) memory, and can also support dual memory channels, both of which should give the machine a performance improvement in the memory department.

We purchased two 512MB SO-DIMM modules rated at PC2-4200 from [Crucial][8], and installed them, first in a single channel, then dual channel configuration. Testing was done using [MemTest86][9], version 3.2.

_Results_

* Single Channel PC2-3200 (As shipped from Dell) - 1176 MB/sec - baseline
* Single Channel PC2-4200 (Crucial memory) - 1385 MB/sec - 17.8% faster
* Dual Channel PC2-4200 (2 x Crucial memory) - 1484 MB/sec - 26.2% faster

As you can see, a memory upgrade can considerably improve the memory bandwidth of this system. Memory intensive programs such as databases, file serving, or content creation and graphics manipulation would all benefit from this system improvement.

Knowing what to buy and how to upgrade can maximize the performance of a system. We routinely offer this and other [services][10] to our customers - please [contact][11] us if you are interested, or just have a comment on this article.

[1]: http://www.dell.com “Dell Computer”
[2]: http://arstechnica.com/news.ars/post/20050412-4805.html “$750 off a $1499 purchase!”
[3]: http://www.kernel.org “Linux”
[4]: http://www.openbsd.org “OpenBSD”
[5]: http://www.microsoft.com “Microsoft”
[6]: http://www1.us.dell.com/content/products/productdetails.aspx/inspn_6000 “Inspiron 6000″
[7]: http://www.intel.com/design/chipsets/mobile/915_fam.htm “Intel Mobile 915 Family”
[8]: http://www.crucial.com/ “Crucial.com”
[9]: http://www.memtest86.com/ “MemTest86″
[10]: http://www.artisancomputer.com/services.php “Artisan Services”
[11]: http://www.artisancomputer.com/contact.php “Contact Artisan”